Hosel designs have changed markedly in the last five years of golf club technology. Callaway Golf innovated the reduced projecting hosel in its Big Bertha.RTM..sup.1 woods club line, and also it innovated other techniques to reduce the weight of the hosel. FNT 1. Big Bertha is a registered trademark of Callaway Golf.
In my U.S. patent application Ser. No. 08/859,282, Filed: May 19, 1997, entitled OVERSIZE METAL WOOD WITH POWER SHAFT, I describe a hosel that includes a short hosel segment projecting downwardly from the top wall and a spaced also short hosel segment near the sole plate designed to reduce hosel weight without the sacrifice of strength.
Because metal drivers cannot exceed the weight range of 198 to 204 grams, every gram of saved weight is critical and, if saved, makes the design and manufacturing tasks far simpler. This is particularly true with stainless steel wood club heads because the trend to larger club heads in the last five years has made it difficult to utilize stainless steel and at the same time enlarge the head. This trend has been aided by the development of titanium alloy heads because these alloys with about 90% pure titanium have only 60% of the weight of stainless steels.
But what has happened is the public demand for heads in excess of 250 cm..sup.3 in volume has created almost the same weight problem in titanium that previously existed in the stainless steel head designs. Therefore, any weight saving technique, such as the one the present invention is directed, is now critical and important in the design and manufacture of titanium alloy heads, almost as much as it was in the smaller stainless steel heads.
Thus, the present invention is directed to devising an improved hosel design of substantially reduced weight without sacrificing the structural integrity of the head or of the received shaft, bearing in mind that today's shafts are primarily graphite compositions and prone to fracture in the area just above the hosel.
Most graphite shaft manufacturers recommend the upper end of the hosel be chamfered and filled with epoxy as the shaft is assembled to the head. This reduces the likelihood of shaft fracture at the top of the hosel, but nevertheless the problem still remains significant.
One aspect to achieving hosel weight reduction lies in the mistaken prevailing view of club head designers that the hosel bore must be deep to prevent shaft fracture and shaft loosening in the hosel. This view is simply false and has given misdirection to the desire to achieve weight saving in the hosel area.
Another misconception is that the hosel must extend a substantial distance above the top wall of the club head. This misconception may be a result, not only of a belief that the upwardly projecting hosel is necessary to support the shaft, but of the cosmetic need to have the hosel gently curve into the surface of the top wall of the club head 360 degrees around the hosel. That is, one reason club designers have not envisioned the elimination of the hosel upward projection from the top wall, is the cosmetic need for blending the lower end of the shaft into the top wall. However, these designers have not appreciated this result can be achieved without the hosel performing the entire cosmetic blending function.
It is, therefore, a primary object of the present invention to ameliorate the problems noted above in the prior art, and provide a golf club head with a shortened hosel and ferrule that reduces hosel weight without sacrificing shaft support or cosmetic integrity.